The present invention relates to an apparatus for processing EPG (Electronic Program Guide) information, a method for processing EPG information and a system for receiving digital broadcasts, which are used in reception of television programs and the like. More particularly, it relates to means which are useful in application to e.g. digital television sets.
Digitization of television and radio broadcasts have been promoted in various countries including Japan. Systems for digital broadcasting include ATSC (Advanced Television Systems Committee) of the U.S., DVB (Digital Video Broadcasting) of Europe, and ISDB (Integrated Services Digital Broadcasting) of Japan. Digital broadcasting is characterized by various types of data capable of being multiplexed in addition to contents data including moving picture data and audio data. Such function is used to deliver pertinent information including a program schedule, which is generically referred to as “electronic program guide” or “EPG” for short, and the license information, participants, outline and home page URL of each program. Thus, the convenience of audience is enhanced.
Further, in the field of mobile devices including portable telephones, terminals which allow users to receive digital broadcasts have been in common use. For example, in Japan, a one-segment partial reception service of ISDB-T (Integrated Services Digital Broadcasting for Terrestrial), commonly known as “one-segment broadcasting” is ubiquitous; and in other countries including Europe, a service such as DVB-H (Digital Video Broadcasting for Handheld) has been started.
Mobile devices are inferior to stationary television sets and PCs (Personal Computers) in hardware performances such as performance of CPUs (Central Processing Units) and capacity of RAMs (Random Access Memories). Digital broadcasting for mobile devices requires a smaller amount of information to be handled in comparison to typical digital broadcasts, however it needs some arrangement in respect of implementation for the purpose of providing users with a comfortable usage environment because of the hardware restriction as described above. Particularly, implementation of electronic program guides, which has a large impact on the user-friendliness, is important.
Electronic program guide data is divided and multiplexed into contents data, and intermittently carried to receiver terminals on airwaves. A receiver terminal, which is going to use an electronic program guide, usually separates EPG data and contents data from received broadcast data, analyzes and organizes information stored in the EPG data, and then constructs a database on RAM. The resultant electronic program guide database is used to prepare an electronic program guide, which will be supplied to users.
It is difficult to accumulate all the information at the time of construction of an electronic program guide database because the capacity of RAM is finite. However, EPG data is multiplexed into contents data and delivered intermittently, and therefore when a user attempts to acquire required information from time to time, a longer time is required to prepare an electronic program guide to be supplied to the user, and consequently the convenience for the user is ruined. Hence, to cope with such problem, a means termed “look-ahead”, by which information likely to be required is acquired in advance, has been used usually.
JP-A-2005-85174 has proposed a technique of such look-ahead. According to the technique, the range to look in advance is determined by computing based on the trail of displacement of a mouse cursor which a user is handling, and the user preferentially gains information more likely to be looked subsequently.